Firstly, I don't claim to be a voice acting expert by any means. What I do know, however, is audio. If you wish to be a voice actor, you must surely wish to do everything in your means to sound as professional as you can.
In order to properly voice act, you shouldn't be limited by your hardware. You need to have the ability to speak softly, and in the next instant yell at the top of your lungs without losing a step. Projecting shouldn't be a matter of turning your volume knob down so you don't clip in the recording. I hear way too many recordings in these forums with dynamic ranges that just don't work. Either I can't hear it, or it's clipping and getting that static sound. Sometimes in the same recording!
I'm here to tell you that compressors are your friends. Some of you may ask what a compressor is. Well let me tell you. A compressor acts like another person turning the volume of your mic input down when you get too loud. While talking softly, the compressor isn't doing anything, but when you yell, and enter the danger zone of clipping, depending on your compressor settings, the volume reduces by a ratio you set. It kinda looks like this:
The vertical line represents when you want the compressor to kick on, the smaller dashes represent the same amount of output, just reduced by a ratio set by you on the compressor itself. Both scenarios represent you screaming like a banshee, but the one with the compressor doesn't clip.
Not only does the compressor limit max output, but using it can also increase the volume of the quiet parts. In essence it "compresses" your waveform. This allows you to get a little frisky with that input volume and actually hear your quieter parts.
I have recorded a line from a fantastic piece of literature, and put it through three different signal processing scenarios: Dry (mic and sound interface only), compressed (only using a compressor), and finally a compressor with EQ and other post processing. With these recordings, I made sure to talk normally, loudly, and quietly in each one, to display volume dynamics.
It sounds okay, a little hard to hear parts. The next one has a compressor added, maybe a little heavy, but you can hear it grab those higher transients and corral them in:
And finally, here is the same recording with Compression, EQ, and other processing effects. You can really hear everything I'm doing:
I hope this helps some people wanting to throw their voice in game. With compression, you can really act your heart out and never worry about levels. Compression is your friend!
Play around with things in your recording software! Save a nice preset, so when you audition for parts, you're consistently offering your best sounding work!